The present invention relates to biocompatible drug delivery methods and systems and, more particularly, to systems and methods for treating cancer of an internal cavity such as the urinary bladder.
The most common form of bladder cancer is transitional cell carcinoma (TCC), involving the cells that line the urinary tract, accounting for more than 90% of bladder cancers. One treatment for patients with early stage bladder cancer is surgical removal of the tumor, known as Trans-Urethral Resectomy (TUR). However, even after complete excision of a superficial bladder tumor, recurrence rates are up to 75%. Although most recurrences are also superficial, bladder cancer is a multi-focal disease and new tumors may not necessarily occur at the same location. Accordingly, a post-surgery monitoring program is always initiated for early detection of recurrence. The standard monitoring procedure typically includes flexible cystoscopic examinations of the bladder every three to four months for the first two years and, in the absence of recurrence, less frequently thereafter.
Flushing of the bladder with different drugs on a regular basis has been shown to significantly reduce the recurrence rate. Specifically, the commonly used agents include Bacillus Calmette-Guerin (BCG), thiotepa, doxorubicin, mitomycin C, Taxol™ and Gemzar™. However, multiple invasive sessions are needed on a regular basis.
Furthermore, it has been shown that during TUR, cells released during surgical excision of the tumor tend to migrate, which can lead to new sites of tumor formation. It would be advantageous to provide means for preventing such occurrences while treating the cancer as well.
The present invention seeks to remedy the deficiencies of the commonly used method of flushing the internal cavity, providing a more constant treatment while protecting unaffected areas.